RANK Expression and Osteoclastogenesis in Human Monocytes in Peripheral Blood from Rheumatoid Arthritis Patients

Biomed Res Int. 2016;2016:4874195. doi: 10.1155/2016/4874195. Epub 2016 Oct 16.

Abstract

Rheumatoid arthritis (RA) appears as inflammation of synovial tissue and joint destruction. Receptor activator of NF-κB (RANK) is a member of the TNF receptor superfamily and a receptor for the RANK ligand (RANKL). In this study, we examined the expression of RANKhigh and CCR6 on CD14+ monocytes from patients with RA and healthy volunteers. Peripheral blood samples were obtained from both the RA patients and the healthy volunteers. Osteoclastogenesis from monocytes was induced by RANKL and M-CSF in vitro. To study the expression of RANKhigh and CCR6 on CD14+ monocytes, two-color flow cytometry was performed. Levels of expression of RANK on monocytes were significantly correlated with the level of osteoclastogenesis in the healthy volunteers. The expression of RANKhigh on CD14+ monocyte in RA patients without treatment was elevated and that in those receiving treatment was decreased. In addition, the high-level expression of RANK on CD14+ monocytes was correlated with the high-level expression of CCR6 in healthy volunteers. Monocytes expressing both RANK and CCR6 differentiate into osteoclasts. The expression of CD14+RANKhigh in untreated RA patients was elevated. RANK and CCR6 expressed on monocytes may be novel targets for the regulation of bone resorption in RA and osteoporosis.

MeSH terms

  • Adult
  • Aged
  • Arthritis, Rheumatoid / blood*
  • Arthritis, Rheumatoid / metabolism*
  • Case-Control Studies
  • Cell Count
  • Fluorescence
  • Humans
  • Lipopolysaccharide Receptors / metabolism
  • Middle Aged
  • Monocytes / metabolism*
  • Osteoclasts / metabolism*
  • Osteogenesis*
  • Receptor Activator of Nuclear Factor-kappa B / metabolism*
  • Receptors, CCR6 / metabolism

Substances

  • CCR6 protein, human
  • Lipopolysaccharide Receptors
  • Receptor Activator of Nuclear Factor-kappa B
  • Receptors, CCR6
  • TNFRSF11A protein, human